


Grown-Up Problems

by ToiletPaperPrincess



Series: Reader-Insert Shenanigans [6]
Category: Undertale (Video Game)
Genre: Awkwardness, Fluff and Humor, Friendship, Gender-Neutral Pronouns, Other, Post-Pacifist Route, Reader-Insert, Reader-Interactive, Romance
Language: English
Status: Completed
Published: 2016-01-11
Updated: 2016-01-11
Packaged: 2018-05-13 04:08:53
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,320
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5694175
Author URL: https://archiveofourown.org/users/ToiletPaperPrincess/pseuds/ToiletPaperPrincess
Summary: <blockquote class="userstuff">
              <p>Apparently Undyne's got some kind of issue with you, but you're too busy being distracted by your bony boyfriend to care.  After all, why should you bother "facing your problems head-on" when "flee" is an option?</p><p>Warning for slight-but-present mature content.</p>
            </blockquote>





	Grown-Up Problems

**Author's Note:**

> This is...kind of a weird one, even for me? The final scene was going to be a bit of an experiment regardless, but then this Undyne thing which was originally a brief side scene unexpectedly wound up morphing into a big sprawling plot. I'm not totally sure how well any of it works, but oh well, I still really like the Alphys dialogue. P: I should write her more.

Out of nowhere, you got a call from Undyne.

You just stood there, in the middle of the grocery store, a half-filled cart in front of you, staring at your vibrating phone.

It wasn’t that you didn’t like her. You _did_. You thought she was amazing and funny and you kind of wanted to be her, except like, with less scales. It’s just that Undyne was... _intimidating_. The time you spent with her always involved a buffer, be it Papyrus, Alphys or your entire monster friend group. That slightly manic look in her eye, her tendency to break things ( _big_ things) with zero effort—it was quirky from afar but absolutely terrifying up close.

Which is why you froze when you saw the caller ID, but also why you picked up the instant you realized it was about to go to voicemail, even though you _hated_ the kinds of people who talked on the phone in the grocery store.

“Undyne?” you said, trying not to sound confused and failing. (You’d never spoken to her on the phone before.)

The response was nothing but static.

Oh, you realized with a heavy sigh, _that_ explained it, she’d accidentally butt-dialed your number and hadn’t noticed. There was nothing to worry ab—

_“ **HUMAN!** ”_

The piercing screech made you lose your grip on the phone, and you scrambled wildly to catch it before it could hit the floor. People were staring. You tried not to think about it.

“Y-y-...yes?”

There was a heavy cough, then a snort, then several throat-clearing noises. You wondered if your thumping heartbeat was loud enough to get picked up by the receiver. It certainly felt like it.

 _“There’s...ahem. Um.”_ She paused for the loudest, phlegmiest throat-clearing you’d ever heard in your life. _“Sorry. I have to...no, no, I’m NOT sorry! HUMAN! LISTEN UP!!”_

You nodded frantically, forgetting she couldn’t see.

_“I-if you keep...uh...then...that might...you could...UUUGH?!?!”_

A sound like splintering wood, and then for several seconds there was nothing but heavy panting.

“Un—” you tried meekly, but were interrupted by a scream.

_“IF THAT HAPPENS, **DON’T DO IT!** DON’T YOU **DAAAAARE!!** ”_

She hung up. Or, based on the noise, skewered her phone with a spear.

Slowly you realized that you were crouching beneath your cart with your arms over your head. Slowly you lowered your arms, crawled out, stood up, gave a weak grin to the shoppers hastily pretending they hadn’t been staring at you, and put your phone back in your pocket.

Needless to say, you bought a lot of comfort food.

***

You were a bit worried about the unfinished conversation, that whatever was upsetting Undyne might make her do to you what she’d done to the phone if you didn’t figure it out and clear it up, but when a full day passed and she didn’t call back you decided you’d rather repress that memory than have another _Psycho_ shower scene dream.

Usually your boyfriend made for a good distraction, but to be fair he also usually said the most hilariously wrong thing at the most hilariously wrong time.

“UNDYNE’S BEEN ASKING ABOUT YOU,” was what he said then, just as you were pulling away from a kiss. Papyrus had his hand on your cheek and everything, and he went in for another kiss after he said it.

“She _what?_ ” you coughed, jerking back reflexively, and he wound up nuzzling your chin instead.

“SHE’S BEEN _ASKING ABOUT YOU!!_ I’M SORRY, ARE MY KISSES MAKING IT HARD FOR YOU TO CONCENTRATE ON THE CONVERSATION? I’LL STOP!”

“I’d rather kiss you than talk about Undyne,” you mumbled, aware of how childish that was even as you said it. But Papyrus chuckled affectionately and pressed his mouth to your cheek, then to your upper lip, then you were back in the rhythm of slow, tender kisses before he let out a satisfied sigh and pushed you back.

“I THINK SHE WANTS TO BE YOUR FRIEND,” he went on as if there’d been no interruption. “SHE WAS ASKING A LOT OF PERSONAL QUESTIONS! OF COURSE, I GAVE VERY FLATTERING ANSWERS.”

You briefly flashed back to a party some weeks before, when you’d seen Undyne and Alphys holding hands across the room, watching Undyne blush and sweat and stammer in a way that’d totally contradicted everything you thought you knew about her. And you remembered hearing about Undyne’s trouble writing letters because they made her nervous. Could that really have been it? Her brash, extroverted personality concealed a crippling social anxiety that made screaming and smashing the phone easier than trying to start a friendly conversation? ...But wait. Then where did “DON’T DO IT” fit in?

A train of thought started chugging away, but Papyrus was gently nibbling your neck so you decided you’d rather keep your thoughts right here.

***

You had Papyrus pressed into the back of an armchair, straddling his lap, hugging him tight, making out with him ravenously. This was actually on a totally separate day from the previous scene, as the two of you were at your place fresh from marathoning a quiz show instead of at his place stealing kisses in between cooking with those same groceries from The Phone Call Incident (which you realize you hadn’t mentioned at the time, but come on, you were a little distracted).

Pap was particularly sensitive tonight, gasping and shivering at each little touch. Even through layers of clothing you were sure his bony fingertips were going to leave bruises, he was gripping you so hard. Kisses came in rough and rapid on both sides, occasionally missing because of how much you were both moving around, but suddenly finding your mouths against each others’ throats or cheeks hardly qualified as a failure.

You were just starting to feel hot under the collar when Papyrus suddenly coughed, thumping his chest with a fist. You pulled back instantly, the armchair rattling beneath you. “Are you all right?”

“OH? _OH!_ THAT.” He waved a hand dismissively. “YES, YES, I’M JUST AS EXCELLENT AS I ALWAYS AM!”

You grinned, red-faced. “You certainly are.”

He smiled back, giggling, but he put significantly less passion into his next mouth-nuzzle and soon was bodily lifting you off of him. “THIS ISN’T A COMMENTARY ON YOUR SMOOCHING PROWESS, WHICH IS QUITE EXCEPTIONAL, BUT I’M AFRAID I HAVE TO LEAVE!! SANS IS WAITING FOR ME. I FORGOT.”

“Oh, yeah, of course.” You were disappointed, and it must have shown because Papyrus immediately wrapped you in a bone-crunching hug, patting your back and kissing behind your ear. You giggled and pushed him away, thumping his shoulder affectionately.

“Go on, go take care of your brother.”

“I SHALL! DO THAT!! GOOD NIGHT!”

“Good night.”

One last kiss and he was out the door, locking it behind him as he always did. With a sigh you collapsed back into the armchair, already replaying the past hour in your mind with a self-conscious smile.

It wasn’t until the signature music came up that you realized with a start that _Psycho_ was playing on the long-forgotten TV. And that reminded you of your nightmare, and _that_ reminded you of _why_ you’d had it, and with a groan you realized you should probably just be an adult already and take care of the problem you’d been putting off for the sake of skeleton smooching.

But you didn’t have to be enough of an adult to tackle the problem head-on. You could still be immature enough to take the back door.

You typed out a text to Alphys.

>Hey, sorry to pry, but I had a weird phone convo w Undyne on Saturday & wondered if you know what was up w that?

While waiting for a response, you switched over to social media and got to watch Alphys liveblog her reaction to your text (“omg phone’s buzzing WHAT’D I DO?!?!?” “lol the bae’s gotta wait [blurry photo of a TV paused on some anime]” “wait what 8V” “UUUUUGH GOTTA TYPE”) before you finally got a reply.

*what kind of weird phone convo???? One of those where she BREAKS HER PHONE lmao WAS THAT YOU’RE FAULT???

*^“your” lol

Your social media pinged. Alphys had posted a partial screencap of the texts—just enough to show the typo and her correction—with the caption “I HAVE A PHD!!!! 8’D”

>I think she did break her phone @ the end but I dunno why

>She just yelled a buncha sentence fragments & sounded mad

*SOUNDS LIKE UNDYNE =^.^= XD

*idk what it was about tho, want me 2 ask her 2 call u back??

>NO

>no wait, actually that might be a good idea

Your social media pinged, and you switched over in hopes that it might ease your anxiety—you didn’t actually _want_ to talk to Undyne again, not without knowing what was going on at least. Alphys was posting a series of _Mew Mew Kissy Cutie_ screenshots and tagging them with things like “me screamin ur name ;D”, “...waiting”, “BABY COME BACK!!!”, “my face when gf makes me get off the couch”, and finally “where r u??????” (In between were a series of selfies from Mettaton, aesthetic posts from a human friend and Toriel posting recipe links.)

*sorry, I think she’s out??? I’ll just text her or else I’ll forget lol

You switched back over to social media. There was a photo of Mettaton doing “duck face”...but in his rectangle form, somehow.

_BAM bum ba ba bum bum_

You stiffened.

That...was not part of the _Psycho_ score.

_BAM bum ba ba bum bum_

Your social media pinged. Alphys was screencapping her outgoing texts to Undyne.

Of course you recognized the music. You’d heard it often enough. That song had been practically playing on a loop at that birthday party when Napstablook had finally finished composing it for—

You peeked behind the armchair.

_BAM bum ba ba bMMMMFFFMMFMMM_

Undyne was crouched there like a feral cat, frantically trying to muffle the sound of her phone by shoving her hands into the offending pocket, staring up at you with wide, horrified eyes.

Someone on TV screamed.

You took a split second to blink and heard the sound of breaking glass. When you opened your eyes again, Undyne was gone and the curtains were flapping over a brand-new hole in your window.

*she’s not responding?? DX maybe her phones’ dead. Or she broke it ag a in lol

*hope she’s ok

*do u thnk shes ok

>I just saw her

*??????

>Please ask her what she was doing in my house

*???????????????????

Your social media pinged. Alphys had made a new text post with just the word “wat”.

It already had three likes.

***

You didn’t call Papyrus even though you desperately wanted to, because he had to go home to Sans and it was more likely he’d make the window problem worse than better and _okay this was a really understandable situation to be understandably rattled by_ but you figured you should just suck it up and Google “broken window fixes” and hope Alphys would come through for you on the “wtf just happened” front. But there was no text response by the time you went to bed with a bath towel duct-taped over the window hole and a heavy bookcase shoved in front of it for extra protection.

The next morning, the bookcase was still in place but there were scuff marks on the floor where it’d been pushed out of the way and dragged back, and when you checked the duct-taped towel was halfway hanging off where it’d been neatly secured before. A fresh pane of glass _exactly_ the size you needed had been placed carefully on the floor with a post-it note on it.

“ **DON’T.** ”

“Don’t _WHAT?!?_ ” you shouted, but no one answered.

***

Alphys never actually wound up responding. Her social media account was pretty dead for a day or so, but then she started posting normally again, so you texted her asking about The Situation and then suddenly her social media posts would stop like she was playing hide-and-seek. Not very mature of her, you thought as you continued avoiding talking to Undyne.

You did wind up talking to Papyrus, though, while taking an afternoon stroll through the park and occasionally stopping to watch people’s chess games.

“AW, UNDYNE CAME TO _VISIT YOU??_ ” was Papyrus’ takeaway from the story. “I _KNEW_ SHE WANTED TO BE YOUR FRIEND!”

“No,” you sighed, “she _broke into my house_. ... _Twice_. There’s a difference.”

Pap squinted dramatically. “...OR _IS_ THERE???”

There was no point arguing, so you let it go. You’d rather just relax and enjoy yourself anyway, no worries, no fear of a seven-foot-tall fish lady popping out of a bush with a spear and screaming “DON’T!!” as she stabs you to death. It was probably nothing anyways, right? It’s not like you were planning to do anything bad, ever, _ever_ , and she was like a defender of justice or something so she couldn’t hurt an innocent person, right? And anyway she was close friends with Pap so she probably wouldn’t hurt you because it’d make him sad. You were probably fine. You could probably ignore it.

“NYEH?? ARE YOU ALL RIGHT?”

You hadn’t been aware of how uncomfortably warm you were until Papyrus removed his arm from around your shoulder and frantically began unzipping your jacket. There was sweat on your forehead, and tiny lights danced in front of your eyes. Good gosh, you really _were_ scared of Undyne, _weren’t_ you?

“I’m—I’m fine,” you mumbled, blinking rapidly. Papyrus’ face was flushed with concern, and his fingers kept twitching like he wasn’t sure whether he should touch you or not.

“YOU SHOULD GO HOME,” he said, finally bringing up one hand to mop your forehead. “I’LL WALK WITH— _OH! SANS!_ ”

He began waving vigorously, and you followed Pap’s gaze to see his brother lounging on a stool behind a hot dog cart. Sans made a show of laboriously climbing down from the stool and waddling over to you, but his self-amused grin receded a notch when he got close enough to see your faces.

“SANS, WILL YOU HELP ME WALK OUR FRIEND HOME?” Papyrus was pleading. Sure, you felt a little dizzy, but you weren’t sure this level of concern was warranted. “I’M NOT SURE IF—”

“Really, it’s okay,” you tried to insist, but Sans had already read some signal from his bro and slung his arm steadyingly around your waist.

“no prob. i haven’t had a break in ten minutes anyway.”

Papyrus gnashed his teeth a bit at that but soon resumed fretting, dancing just ahead of you and watching your footsteps nervously even though you were walking as easily as you ever did. Sans’ grip was oddly tight, though, so you did stumble once or twice, but you tried to keep up a friendly conversation to put the brothers back at ease.

“S-so, uh, a bunch of my friends just got hired at that new spider bakery downtown. They said it’s kinda creepy but the owner’s really nice.”

“hmm, i guess humans _would_ be ‘bugged’ by that kind of atmosphere.”

“SANS! YOU’RE MAKING THINGS WORSE!”

“I mean, though, all the food is made out of spiders, but spiders also eat it, so...is that like, a normal monster thing? I’m not, I’m not judging, I’m just curious I guess—”

“PLEASE, THIS IS NOT THE TIME TO THINK ABOUT EATING SPIDERS.”

Which was honestly true, so you hurriedly wracked your brain for more conversation topics. You kept accidentally bumping Sans with your arm, so—

“So what’d you guys do the other night?”

Sans gave you an odd look. “...slept?”

“WELL, _ONE_ OF US DID BECAUSE _ONE_ OF US IS A BIG OLD LAZYBONES!!” Papyrus snorted, almost walking backwards into a mailbox. “BUT, EH, FOR ONCE I SUPPOSE I MUST ENCOURAGE HIS BAD EXAMPLE BECAUSE _YOU_ ARE PROBABLY IN NEED OF SL—”

“Oh, no, I meant...two days ago. You forgot that you’d made plans with Sans and had to leave early, remember? I was just wondering what...”

Papyrus missed the mailbox but hit a telephone pole instead, stumbling around dizzily to the amusement of the other pedestrians.

“ _two_ days ago...?” Sans said slowly as if trying to remember.

“DON’T CHANGE THE SUBJECT!” Papyrus barked, dusting himself off. Then he forcefully swept you up into his arms—and since Sans still had a grip on you, he wound up getting lifted too, smushed between you and Papyrus’ ribcage. “I’VE HAD ENOUGH OF YOUR BACKTALK, DATEFRIEND!! YOU’RE GOING HOME AND _SLEEPING!_ ”

He took off at a brisk jog, and honestly his place would’ve been much closer than yours but he trekked all the way there anyways. It didn’t take long for Sans to start snoring.

When he finally set you down outside your front door (Sans stayed clinging to his chest like a koala), though, Pap was back to anxious pampering. “I’M SORRY FOR TREATING YOU SO ROUGHLY,” he whimpered, smoothing down your hair and straightening your jacket. “I’M JUST WORRIED, ALL RIGHT? HUMANS ARE SO STRANGE AND FRAGILE, I JUST...I WANT YOU TO BE SAFE.”

You couldn’t help but smile, and it was clumsy going but you managed to circumvent Sans to give your boyfriend a kiss on the cheek. “All right. I forgive you. But seriously, I’m fine—I’m sorry I made you worry.”

Papyrus exhaled deeply, patting your hair once more for good measure. Then he glared at the lump hanging off of him. “I’D BETTER GET SLEEPY SANSY BACK TO HIS POST,” he grumbled, wrapping his arms around his brother. “PLEASE CALL ME WHEN YOU WAKE UP SO I KNOW YOU’RE FEELING BETTER!!”

You nodded, and waved, and watched him leave. But still you stood in the doorway, feeling slightly disconcerted. You finally made up your mind to run after him—

“OH, UNDYNE!! WHAT ARE _YOU_ DOING HERE???”

You ducked into your home and triple-locked the door.

***

“So...how was Undyne...?”

You were curled up in bed with the phone to your ear. You’d tried sleeping just because you’d promised (and you _had_ felt a little warm again when you’d said goodbye), but it was the middle of the day and you kept jumping at every pointy-looking shadow so it hadn’t really worked. But Papyrus didn’t need to know that.

_“OH, SHE WAS IN A HURRY TO GO SOMEPLACE. SHE SEEMED QUITE SURPRISED TO SEE ME!! OR, ‘US’, I SUPPOSE. NOT THAT SANS WOKE UP ENOUGH TO PARTICIPATE IN OUR SCINTILLATING CONVERSATION.”_

“She didn’t say anything about why she was hiding behind my armchair, did she.” You didn’t even let your voice rise to indicate a question, you were so sure of the answer.

_“SHE WASN’T HIDING BEHIND YOUR ARMCHAIR! SHE WAS HIDING BEHIND A TRASH CAN AROUND THE CORNER!”_

“No, I mean last t—wait, _hiding behind a trash c_ —uuuuuugh.” You pinched the bridge of your nose. There was a headache coming on.

_“SHE MUST HAVE BEEN WORRIED ABOUT YOUR HEALTH AS WELL!”_

“Yeah, okay.”

There was a very long pause.

...You thought about asking again about his whereabouts the other night. It was probably nothing. But Sans’ reaction to the question...and he hardly _ever_ reacted to _anything_...

_“DATEFRIEND? DID YOU FALL BACK ASLEEP??”_

“Oh, uh, no, Pap. I didn’t.”

_“OH. BUT YOU WERE VERY QUIET. IF YOU WANT TO SLEEP, I’LL JUST...”_

He trailed off, and you couldn’t think of anything to say, so after another few moments of silence he whispered _“SWEET DREAMS”_ and hung up.

***

This time you _did_ fall asleep, and when you woke up from that same old _Psycho_ nightmare it was nearly midnight. But you were wide awake and your head hurt and you thought you might throw up and you were angry, or sad, or scared, or _something_ , and whatever it was it just plain needed to stop.

Your phone hadn’t been doing you any good this week so you left it behind, as objectively dumb as that was. You threw on your jacket, grabbed an impromptu weapon (a table lamp) _just in case_ , and at least had the presence of mind to make sure your keys were in your pocket before you stalked out the door.

There were people around, and lights, and cars, so you started to feel a little silly for carrying around this big old lamp like a baseball bat. But no one bothered you, probably because you were carrying around this big old lamp like a baseball bat, so it evened out.

You hadn’t been totally sure where you wanted to go, and everything looked different at night, so it took longer than it ought which only boosted your adrenaline agitation. But finally you reached Papyrus’ house.

It was so dark out that you felt guilty, but there was a light on inside (of course, Pap hardly ever slept) so you felt less guilty. You raised your fist to knock.

And were violently yanked backwards.

“ _Thought you’d sneak past me?_ ” hissed Undyne. She’d pulled so hard that you’d lost your footing and had fallen into her arms, staring up at her glaring down at you. “ _Well, it didn’t work! I caught you. GO HOME!!_ ”

You swatted at her with the table lamp. It just whooshed through empty air, but it distracted her long enough for you to get back on your feet and face her.

“ _What’s WRONG with you?!?_ ” you whisper-screeched, standing outside your monster boyfriend’s house uninvited in the middle of the night attacking a woman with a table lamp. _“Why are you doing this?_ ”

On your next swing, Undyne grabbed the lamp and tried to wrestle it out of your hands. “ _What’s wrong with YOU? All my warnings and you’re STILL—_ “

“ ** _Warnings about WHAAAAAT?!?!_** _You just kept saying ‘DON’T DO THE THING’ without telling me what ‘THE THING’ is!!_ ”

“ _IT WAS OBVIOUS!!_ ”

“ _OBVIOUSLY NOT!_ ”

“ _W-well...if you didn’t know, you sh-sh-should’ve just ASKED ME??_ ”

She tore the lamp from your grip while you were distracted by her stutter, then she held it out with the lampshade touching your throat, as if she had you at swordpoint. She was panting, and sweating, and her face was red, but you were sure none of it had to do with exertion.

“I won’t let you hurt him,” she half-whimpered, digging the lampshade into your neck. “I’ve been nice so far, but...I’ll do _anything_ to stop you from hurting him.”

You just stared at her. All the rage and pain and sad and nausea had been startled out of you, and you were powerless.

“You...you think I’m gonna hurt Papyrus?” you croaked.

An expression of guilt flitted across Undyne’s fishy face. “Not...uh, not necessarily that you’re _gonna_ ,” she mumbled. “But...you _could_.”

“I won’t!” The mere thought of it had your head spinning. “I would _never!_ ”

“But you _could._ ”

...

“...could _what?_ ”

It was a simple question, clumsily vague, but it lowered the lamp.

“Uh,” Undyne fumbled, glancing to the side. “You— _you know_.”

“No...no, we just established that I _don’t_.” You stepped forward, and Undyne lurched back. “Okay, fine, _now_ I’m asking. _What_ are you afraid of me doing?”

Undyne waved the lamp haphazardly. If it was lit, she’d look like she was guiding an airplane down a runway. “N-none of your business! Just so long as you don’t _do it!_ ”

“You have to _tell me what it is_ before I can make sure to _not do it_.” She started to stammer out a reply before you changed your mind and steamrolled over it. “Actually, you know what? Maybe I _won’t_ not do it. I’m not promising not to do _anything_. Why should I listen to you? You sent me a threatening phone call, broke into my house, I’m pretty sure you’re _stalking_ me, so maybe—”

Whether it was out of hating your sass or enjoying your list of her accomplishments, Undyne snapped out of it. Within a second she was behind you, pressing the lamp against your throat, gently but _surely_ choking you.

“YOU LITTLE _SLUG-HOLE!_ ” she bellowed as you clawed desperately against her scaly arms. “I’LL MAKE _SURE_ YOU NEVER GET A _CHANCE_ TO EVEN _CONTEMPLATE_ —”

“NYHELLO?”

Undyne’s grip loosened enough for both of you to whirl around. Papyrus was silhouetted in the doorway, a sternly cheerful look on his face.

“WOWIE, DATEFRIEND, I DIDN’T KNOW YOU WERE TAKING COMBAT LESSONS WITH UNDYNE!!” he was announcing, but his pose remained tense. He knew you weren’t, he was just giving you an out. “WHY DON’T YOU TWO COME IN AND HAVE SOME SPAGHETTI? YOU MUST HAVE WORKED UP AN APPETITE!”

Undyne hesitated, but finally she _did_ release you, stomping out from behind you towards the doorway. Papyrus relaxed into a more genuine smile.

Now that you were no longer in the middle of a near-death experience, you noticed the other lights and murmurs coming from the surrounding houses. You gulped. This had been one step away from ending with police sirens.

Before she entered the house, Undyne slapped the table lamp into Papyrus’ hands. He stared at it.

“WHAT’S THIS?”

Undyne shot you a glare before sneering the answer.

“You ‘light up my life’.”

***

Papyrus wasn’t kidding about the spaghetti, cold leftovers straight from the fridge, and both you and your antagonist felt obliged to eat it. The silence was made almost more awkward by Pap’s attempts to fill it, chattering loudly about how you and Undyne must have become such great friends as if he could simply speak it into being.

At last you couldn’t take it anymore. You slammed your plate down onto the table.

“Are you in love with him?” you demanded of Undyne.

She spat out her food, gaping at you with noodles hanging off of her sharp teeth.

“ _What the hell?_ ” she coughed, glancing from you to the equally startled Papyrus. “Where did _that_ come from?”

You gave her a _look_. “You tried to kill me because you were afraid I might hurt his feelings.”

Undyne snorted. “Pfffft. No I didn’t.”

Was she really going to commit this hard to the bit? “Undyne, I just described what literally just happened.”

“Are you _kidding_ me? That—”

You weren’t joking. Neither was she.

“You thought I was going to _physically_ hurt—?” you blurted out.

“Yeah, duh, why else would I _try to kill you?_ No offense, Papyrus.”

He gave a strained grin, sweating nervously. “ACTUALLY, I’M VERY GLAD YOU WOULDN’T KILL SOMEONE JUST FOR HURTING MY FEELINGS?”

“Thanks.”

“BUT, UM—”

“ _How could I even hurt him??_ ” you persisted. “He’s like twice my size, _and_ a monster!”

“THAT’S AN AGE-OLD HUMAN MISCONCEPTION, ACTUALLY, MONSTERS ARE VERY GENTL—”

“I’d be more in danger of _him_ physically hurting _me_ than the other way around! No offense, Papyrus.”

“BUT AS I WAS SAYI—”

“ _THAT’S BECAUSE YOU’RE THINKING ABOUT_ BODIES!” Undyne screamed, finally fed up with your ignorance. “YOU HUMANS, YOU _NEVER_ STOP TO THINK ABOUT _SOULS!_ ”

Then she sat down in a rush, expression like a deer in headlights, trying to stick to her guns but obviously freaking out internally.

“I thought you said this _wasn’t_ about hurting his feelings,” you tried, but no one responded. Papyrus had stiffened up too, nervously fumbling with his hands and avoiding your gaze.

Both of them were red-faced.

You rubbed your eyes with a sigh. “...Someone,” you announced, “is going to have to tell me what’s going on.”

“GOLLY-GEE, I FORGOT TO TUCK SANS INTO BED!” Papyrus shrieked, bumping the table hard as he stood up. You grabbed his wrist before he could leave.

“ _Not this time_ ,” you scolded. A situationally-inappropriate smile tried to twitch its way onto your face. Man, being a responsible adult was a power trip.

Pap squirmed and whimpered, but eventually he sat back down, wrist dangling limply in your hand. He dropped his flaming-red face into his spaghetti.

Undyne’s leg was jiggling nervously, and you were concerned she might make a break for it to. But she just sat there sinking her teeth into her lower lip while her gills flapped wildly with her ragged breaths.

“What about souls?” you prompted firmly.

“‘What about souls’,” Undyne mocked under her breath, shooting you a pained glare when you looked at her. “ _Everybody_ knows...”

“I DIDN’T.”

Papyrus said it before you could, the noise muffled through the spaghetti.

“I DIDN’T KNOW,” he repeated. “NOT UNTIL I DID SOME RESEARCH AFTER WE TALKED. AH—OF COURSE, I KNOW WHAT SOULS _ARE,_ WHY WOULDN’T I KNOW WHAT SOULS _ARE_ , BUT—” Without lifting his face from his plate, he turned to look at Undyne. “IS _THAT_ WHY YOU’RE MAD? BECAUSE I TOLD YOU WHAT MY SOUL WAS DOING??”

Undyne grunted, but apparently that was enough.

“UNDYYYYYYYYYNE!! YOU’RE ALWAYS PUNCHING YOUR PROBLEMS IN THE ARM AND RUNNING AWAY! YOU DIDN’T EVEN _NEED_ TO PUNCH THIS PROBLEM!! I ALREADY CAME TO THE LOGICAL CONCLUSION THAT I SHOULD PUNCH MY PROBLEM IN THE ARM UNTIL _IT_ RAN AWAY.”

“ _What problem?_ ” you tried to interject (“what his soul was doing”...??), but they weren’t even listening.

“You mean you weren’t gonna—?” Undyne gasped.

Papyrus shook his head, sloshing noodles everywhere. “OF COURSE NOT! IT WOULD BE TOO DANGEROUS!”

Undyne crowed with laughter, banging her fist on the table. “ _I TOLD YOU!_ ” she gloated at you. “I _TOLD_ YOU YOU COULD HURT HIM! BUT DID YOU LISTEN??”

“WHAAAAT? WHO HURT _WHO?_ ” Finally Papyrus lifted his head, tomato sauce ironically coating his face like blood. “ _I_ DIDN’T WANT TO HURT MY _DATEFRIEND!_ _THAT’S_ WHY I DECIDED WE SHOULDN’T DO IT!!”

“ _Do what?_ ” But it was no use.

“How could you hurt _them??_ You know the power difference between monster souls and human souls, if anything _you—_ ”

“‘POWER DIFFERENCE’? UNDYNE, IS FIGHTING THE ONLY THING YOU MAKE BRAIN SPACE FOR?? I DIDN’T WANT TO HURT THEIR _FEELINGS!_ OR, UM, M-MY FEELINGS.”

He gulped, and you were too frightened by his sad expression to take advantage of the pause.

“HUMANS...” he sighed, “HUMANS DON’T _MERGE_ LIKE THAT, YOU KNOW? I WAS...I WAS AFRAID...”

“Oh, _Papyrus_ ,” you murmured sympathetically, transferring your grip from his wrist to his hand and twining your fingers in his. But still...you couldn’t resist. “ _I have literally no idea what you’re talking about._ ”

Pap gazed into your eyes for a moment. Then he screwed his eyesockets shut and took in a deep, shuddering breath.

You started to feel warm again, and tiny pinpricks of white light spun before your eyes.

But—but it wasn’t _you_.

Heat was radiating from Papyrus’ chest cavity, which is where the lights were congregating. As you watched, a stronger glow began to emanate through the fabric of his shirt, casting his ribs in dark silhouettes.

You’d felt this before, and not just at the park. You glanced at him questioningly, but his eyes were still shut. Beads of sweat stood out like bullet holes on his forehead.

Soon enough Papyrus cleared his throat and whacked his sternum with his free hand. The light was snuffed out. He shuddered mightily as if he’d just swallowed something gross.

“I...DIDN’T NEED TO HURRY HOME TO SANS THAT NIGHT.”

You shook your head reflexively, stunned.

“AND WHEN I SUDDENLY EXCUSED MYSELF TO WASH MY HANDS THAT OTHER DAY, AND SPENT A SUSPICIOUS AMOUNT OF TIME CROUCHING DOWN TO TIE MY SHOES THAT _OTHER_ OTHER DAY, AND POSSIBLY MORE UNTRUTHS THAT I’M FORGETTING...I’M VERY, VERY SORRY TO HAVE LIED!! I TRIED TO BE EXTRA-TRUTHFUL AFTERWARDS TO MAKE UP FOR IT. BUT I _WAS_ SINCERELY WORRIED ABOUT YOU IN THE PARK TODAY! FOR REAL. I JUST, EH, NEGLECTED TO MENTION THAT IT WAS KINDA-SORTA-MOSTLY-COMPLETELY BECAUSE OF MY EMBARRASSING CONDITION. THROUGH NO FAULT OF MY OWN! WELL, YES, A FAULT OF MY OWN, AS FEW OF THOSE AS I HAVE, BUT IT WAS AN ACCIDENT! I WOULD NEVER HURT YOU!!”

“I wasn’t hurt,” you reminded him.

“BUT...YOU COULD HAVE BEEN.”

At length, he cleared his throat and squared his stance, still holding your hand.

“HUMAN LOVERS MERGE BY FITTING THEIR BODIES TOGETHER LIKE PUZZLE PIECES,” he explained shakily. “IT’S VERY ODD AND FASCINATING?? AND THERE ARE SO MANY DIFFERENT COMBINATIONS! I HAD ABSOLUTELY NO IDEA!! IT JUST GOES TO SHOW YOU CAN LEARN SOMETHING NEW EVERY DAY!

“BUT...BUT MONSTER LOVERS...DON’T...DO THAT. INSTEAD, WE...”

He gestured at his chest cavity, hoping that would suffice for an explanation, but damn were you ever ignorant. Of course you’d wondered about monster sex, but had thought that it’d be grossly immature of you to look it up. Whoops.

“... _MONSTER LOVERS C-COMBINE THEIR SOULS_ ,” he finally spluttered, convulsively squeezing your hand. You jumped, and he misconstrued the reason, hurrying to apologize. “SEE?? I KNEW THAT WOULD SCARE YOU! A-AND HUMANS MAY NOT EVEN BE ABLE TO DO IT! AND...AND _I_ CAN’T DO WHAT HUMANS DO...SO...”

“...so you just ignored the problem and hoped it would go away,” you mumbled, abashed.

“IT SEEMED LIKE A VERY GOOD IDEA AT THE TIME!”

You rubbed your thumb against his hand for a while before turning to Undyne. “So...why were _you_ upset?”

She was boiling with embarrassment, both her arms and legs crossed and sweat evaporating the same instant it formed, but she found the energy to give you a nasty look. “You may be a little shrimp, but even _you_ could kill him if his soul was exposed,” she grumbled. “I didn’t wanna take that chance.”

“You could have trusted me.”

“But what if I was wrong?”

“ _That’s kinda the point of trust?!_ ”

You weren’t sure where it’d come from, but there it was. You took in a deep breath.

“You both should have trusted me enough to tell me _what the ever-lovin’ hell was going on_ ,” you said, and your voice wobbled because the fake authority was gone. You really meant it. “And to trust me to make the right decision. And...I should have trusted you enough to ask you directly. Both of you. Sorry for being a wimp.”

Undyne got a snort out of that, and you grinned back, and maybe you two _could_ really be friends.

“I LOVE YOU SO MUCH??!” Papyrus suddenly sobbed, flinging his arms around you. You hugged him back fervently, and felt his bony body start to warm...

“That’s enough of that,” grunted Undyne, pushing you two apart.

“GROUP HUG??” Papyrus asked hopefully, stretching one arm toward her, but she was already in your face.

“ _You’re not gonna do it, right?_ ”

You swallowed heavily before you answered.

“...I don’t think that’s any of your damn business.”

***

You would’ve had that black eye for days except for the remarkable healing properties of monster food. But Undyne had gotten an hour-long lecture on the value of friendship from a scarily angry Papyrus, so you figured you were more than even.

Alphys seemed to have heard that there was no longer any dispute for her to be the hapless middleman of, as she was back to answering her texts. She also sent, unprompted (and you politely left them unacknowledged) links to several Undernet articles about “soul merging” that proved suspiciously helpful to your and Pap’s research. All those times you’d seen her and Undyne together and thought that glow was just a trick of the light...good old Al was just a horny little weirdo like the rest of us.

And now...you were here.

Here a week later in Pap’s bedroom, sitting awkwardly side by side in the dark on his racecar bed.

“S-SO?” His knees were jittering frantically. “I’M READY, I’M _VERY_ READY, BUT UM, I JUST WANTED TO CHECK IF _YOU’RE_ READY.”

“I’m...I guess I’m as ready as I’ll ever be.” You cleared your throat, going down the checklist in case that eased the tension a little. “I’m dressed light so the heat won’t be a problem”—you were wearing the thinnest top you had, a pair of shorts, and since you’d taken off your shoes and socks you were barefoot—“and we’ve got the emergency water bottle in case of dehydration”—it was perched on the end table—“but...uh....”

“WHAT?!? BUT WHAT??”

You changed your mind before you spoke, pointing at the water bottle. “But, uh...it’s so close to the bed, so...I mean, it’ll be easy to reach, but what if it gets...knocked over...?”

“AHHH!! RIGHT!” Papyrus sprung to his feet, reaching the table in a single bound. He shunted it clumsily away from the bed, accidentally knocking over the knickknacks littering its surface and diving to the floor to retrieve them. You got halfway up to help, but he’d already finished by then and was just standing nervously in front of you, rubbing his gloved hands together.

“We don’t have to if you don’t—” you tried, but he just blurted out “I WON’T BE MAD IF YOU CAN’T DO IT!”

“JUST. UM.” His entire skull was red. “IT’S OKIE-DOKIE IF IT DOESN’T...ACTUALLY... _WORK_. OF COURSE, I HAVE EVERY CONFIDENCE IN YOU! AND I’M SURE DREAMS COME TRUE IF YOU BELIEVE! BUT...YOU UNDERSTAND?? PLEASE?”

You nodded forcefully, swallowing your own doubts. “I mean, we won’t really know unless we try.”

He plunked himself back down beside you, breathing heavily. “Calm down,” you murmured, as much for yourself as for him, as you placed your hand on his arm. He jumped at the contact. “It’s...it’s best to relax for this, remember?”

“YES. I CAN RELAX. I AM AN EXPERT AT RELAXING!!” Pap took your hand in his own and gripped it tight, then realized the mixed messages there and loosened his fingers, stroking your hand gently instead. You breathed in and out very slowly as he did so.

“OOH! HERE COMES MY ‘BONER’!!”

You laughed, muffling the sound against your shoulder. Sure enough, a faint glow was starting to illuminate his chest cavity, more visible than ever in the dark room. The research and Papyrus’ personal experiences had concluded that this reaction was caused by deep-rooted feelings of love rather than any kind of hormonal stimulus, but given the circumstances you two couldn’t help but see a parallel to human arousal. Mostly Papyrus just liked that this slang word had “bone” in it.

“Are you ready?” you whispered, wrapping your arms around his neck.

The sight of a grinning skull dramatically underlit in the darkness should have been objectively horrifying, but it was the most endearing thing you’d ever seen.

“AYE-AYE, CAPTAIN.”

Putting his hands on your waist, Pap shifted to face you and closed his eyes.

Kissing hadn’t been specified in your research. Not that the research had been particularly helpful in crafting a routine, as the exact process of merging differed greatly from monster to monster (and now to you). But the glow of the soul was fueled by love, and staying relaxed was important, so this seemed like a good option. (You two had had plenty of practice making out, after all.)

This time you were slow and gentle, letting kisses linger for as long as they could, breathing softly through your noses, savoring the feel of the other’s body inch-by-inch under your fingertips. You could tell that Papyrus’ glow was getting steadily brighter even through your eyelids, and you murmured words of praise and encouragement against his teeth. The warmth brought beads of sweat to your skin, but now that you were expecting it (and dressed for it) it wasn’t at all unpleasant. It was...cozy. It was nice.

You hugged Papyrus a little tighter.

Then your breath hitched, and your fingers dug into his shirt. “ARE YOU OKAY??” he asked instantly, hand going to your cheek.

“Yes, yes,” you gasped, swallowing your spit, and tried to calm your breathing. Pap waited, stroking the back of your neck, the pulsing glow of his ribcage like a signal beacon. You let out a sigh and kissed his collarbone.

Then the feeling was back, of something hot trying to force its way up from your stomach, like coughing up fresh soup in slow motion. You whimpered, burying your face in his shoulder, trying to shove the feeling back down.

“DATEFRIEND! DATEFRIEND, ARE YOU—?”

Papyrus shoved you roughly off, holding you out at arm’s length. Your eyes flew open long enough to see it—a tiny spark of colored light dancing out of your barely-glowing chest. But your attention was quickly diverted as Pap turned your face away, towards his, dabbing frantically with his thumbs at the splotchy tears you hadn’t realized you’d been sobbing.

“ARE YOU HURT? DID _I_ HURT YOU?? I SHOULD NEVER _EVER_ HAVE TOLD YOU, I _KNEW_ YOU’D SACRIFICE YOURSELF TO PLEASE ME AND THERE ARE _MUCH_ EASIER WAYS TO PUT A SMILE ON MY FACE, YOU KNOW, WE COULD PLAY SOME _CHECKERS_ —”

“I’m fine! I’m sorry, I was...it was kind of scary.” You tried to grin to ease his dismay. He just shook his head in self-punishment.

“NO, NO, IT’S A RISK YOU SHOULDN’T HAVE HAD TO TAKE! I SHOULD HAVE KNOWN BETTER. I MEAN, I _DID_ KNOW BETTER!! BUT YOU—”

“ _I wanted to do this._ It’s okay.”

Papyrus had forcibly snuffed his soul-glow as soon as he saw you struggling, but even now his concern and affection were slowly lighting it again. The sight of it meant more to you than any words could convey.

“I want to try again,” you said firmly, despite the quiver in your voice. You hurriedly amended upon seeing his expression. “Just one more time. Okay? I know what to expect now, sort of. And...and hey, at least it kinda looks like humans are able to do it, right?”

Pap was still regarding you mournfully, his glow flickering under his face like candlelight. “YOU DON’T HAVE TO DO THIS.”

“But I’m choosing to. Okay? It’s my choice. And...and if it really looks dangerous, we’ll stop right away. All right?”

Taking his hand in yours, not pulling him so much as guiding him along, you lowered yourself onto the bed. Papyrus followed suit, half-reluctantly. Still holding hands, you were now both on your sides on the mattress, facing each other.

You took in a deep breath. “Ready?” you asked again.

Pap leaned forward, and you readied yourself for another kiss.

But instead he released your hand and wrapped his arms around you, pulling you against him in a tender hug. His ribcage pulsed hotter as he held you, his face buried in your shoulder.

“I LOVE YOU,” he said. “UM. OBVIOUSLY. BUT...IT WAS NECESSARY TO REPEAT IT! I’LL REPEAT IT SO MUCH, YOU’LL GET SICK OF HEARING IT!! YOU’LL SAY ‘PAPYRUS, I LITERALLY CANNOT STAND ANOTHER MOMENT OF YOU DECLARING YOUR AMAZING AFFECTION FOR ME’ AND I’LL SAY ‘I’M SORRY, BUT NOT TELLING YOU HOW MUCH I LOVE YOU IS ONE THING I CANNOT DO! EVEN THOUGH I LOVE YOU SO MUCH!!’”

Tears rolled down your face again, but a different kind, and they were washing over a wide smile. “I love you too,” you whispered as you hugged him back. “I love you too.”

It came in the rhythm of his fingers trailing up your spine. That heat again, and even when expected it couldn’t help but be terrifyingly strange. You started to panic again, biting your lower lip as your breath whistled rapidly through your teeth, but though his grip on you tightened Pap just went on talking into your ear.

“IN...ONE, TWO, THREE...OUT...ONE, TWO. I LOVE THAT LITTLE NOISE YOU MAKE WHEN YOU’RE EATING MY SPAGHETTI! IN...ONE, TWO, THREE...OUT...ONE, TWO. I LOVE THAT COOL DANCE MOVE YOU DO THAT YOU’RE TOO EMBARRASSED FOR SOME REASON TO DO IN FRONT OF ANYONE ELSE?? IN...ONE, TWO, THREE...OUT...ONE, TWO.”

You found yourself breathing with the rhythm of his counting, a trick you’d discovered in one of the articles that had clearly stuck more in Pap’s brain than in yours. All the time he went on stroking your back and nuzzling his mouth against your neck. You tried to blubber something in return, list all the things you loved about him, but you weren’t sure whether you’d actually managed to say any of it aloud.

Whether it was by relaxation or distraction, you soon found your entire chest cavity light and warm, though not as warm as Papyrus. There was still a bit of discomfort, but somehow you knew that it would go away with practice. You hadn’t so much as known you _had_ a “soul” until recently, after all.

Pap had fallen silent, his breath coming in almost perfect rhythm with yours. And that wasn’t the only thing. His bright chest cavity was pulsing gently, just once every several seconds, but it was happening at almost the same rate as yours.

An even brighter light was forming just below his collarbone.

You gently pushed back in order to see it, eyes wide with wonder, and Pap did the same, gazing down at this strange space between you. Wild shadows were cast on the wall as a small ball of white light, vaguely heart-shaped, started to collect out of smaller glows swirling around him.

You noticed for the first time that your chest was glowing too, again not quite as bright as his—like a firefly next to a lightbulb. But it was there, and there were little sparks dancing around you as well. They felt... _you_ felt the call of his soul, and the sparks gathered nervously together in imitation.

You gulped loudly, and Pap fixed you with a questioning gaze. But you nodded, gathering your strength—and gently pressed your lips to his mouth.

There was a blinding flash.

Then it was like...like you no longer had a body, but were also hyper-aware of your body all at once. Everything tingled, only “everything” wasn’t you, at least the you you thought you knew. There was a scream of joy, loud in its silence, a beacon of pure ecstasy lighting the universe. You were fire and water. You were everything and nothing. You were the tectonic plates of the Earth’s crust, sliding over and under itself, barely encapsulating the bubbling wellsprings of heat threatening to burst through any unguarded crack. You were air, whistling at mach speeds through a void of stars, laughing and crying simultaneously.

And you were Papyrus, but you were also _with_ Papyrus. You were his love and your love and both your loves together, but you also felt it all, great nebulas blossoming in space from the enormous force of this incredible feeling.

And his fingers were still pressed into your waist, and you were still kissing him hard, and it slowly came to you that the soul merging was long over.

Every muscle in your body was relaxed, leaving you feeling as limp as a rag doll. You gasped wildly for breath, shivering against Pap’s suddenly colder body as he shakily adjusted his grip on you.

“...WOWIE,” was all he managed to say.

You tried to turn your head to look at him, but your body wasn’t ready to move yet. “Was it—did you feel—?”

“MMHMMM, MMMHMMM.”

He started laughing, and he hugged you again, shouting excited congratulations for your amazing feat, and showered your neck with kisses, and you laughed too. But then his thighbone nudged higher than it meant and you both felt it and stopped laughing.

“AH—” Pap pushed you back gently, looking down with concern. “DATEFRIEND, YOU’VE, UM, YOU’VE...SPRUNG A LEAK??”

The stain was obvious against your shorts. So that experience hadn’t just been a _metaphor_ for sex...at least, not so far as your body was concerned.

“I’m so sorry,” you squeaked, screwing your eyes shut in embarrassment. You still didn’t have the strength to throw your hands over your face yet. “I’m _so_ —”

“NO, NO, DON’T BE AFRAID! IT’S JUST THAT...IF IT’S UNCOMFORTABLE, PERHAPS YOU SHOULD...”

His fingers gently met your waistband, and at a mortified nod from you he slid the shorts down over your legs, doing the same for your undergarments once he realized those had it worse. Ever the gentleman, he didn’t look, carefully pulling your shirt down to cover you as he gingerly removed the soiled garments. Then he stood up while you just lay there. It figures, soul-merging was kind of a monster thing, no wonder he was recovering faster than you were.

Papyrus had been about to go for the door when he suddenly turned on his heel, pivoting in place to face you again. In the low light you could really only see him in silhouette, but it was clear he was glancing between the clothing in his hands and your half-naked form on the bed.

“YOU KNOW,” he said slowly, and it seemed like there was an actual glint in his eye sockets, “MONSTER DETERGENT HAS EXCELLENT STAIN-FIGHTING POWERS. IT SHOULDN’T MAKE ANY DIFFERENCE IF THESE DON’T GO IN THE LAUNDRY IMMEDIATELY.”

A shiver ran down your whole body, and not just from the cold. “Oh...?”

Before the shorts had time to land on the floor Pap had already flung himself back onto the bed, wrapping you in an excited embrace and pressing hard kisses all over your face. You reciprocated as eagerly as your exhausted body would allow. Now you were on your back and he was flush on top of you, rocking you back and forth while the mattress creaked underneath. Another faint, almost imperceptible glow was already starting to form deep in his ribcage.

You’d finally gotten some motor control back and were tickling up and down his vertebrae when a faint buzzing emerged from the pocket of your discarded shorts. Your phone was ringing. It was probably Undyne, you’d made plans to play video games at her apartment tomorrow afternoon but had never finalized a time.

Papyrus tried to sit up, but you shushed him with your tongue against his teeth. “I’ll call back later,” you whispered.

Right now, it was time to be an _adult_.

**Author's Note:**

> (I know I'm the worst for throwing that Spongebob joke in the middle of that steamy scene but I am NOT SORRY and I'll LAUGH ABOUT IT FOREVER)


End file.
